I have an 05 6.0 psd 105k. Just bought it and did the brakes, oil and filter and about to do the fuel filters. Should I change the transmission fluid? ? My dad states he never changed his, and has heard of people having transission issues after they change their fluid.

 

I would change it along with the differential oil. Be sure to do the complete trans service which includes the torque convertor and screen. If 4x4, also the transfer case. That way you'll know where you stand with the maintenance.

 

I think it's a good idea to get all the debris out of the transmission on a regular basis. Even if you never cook the fluid, there is still fine abrasive debris generated that warrants acton in my opinion. Cleaning the pan, magnet, replacing the filter, and fresh fluid are easy DIY in the driveway steps you can take to help keep your transmission happy.

 

How do you get the fluid out of the torque converter on this trans?

The inside filter (or "screen" as you call it) does not need to be changed during the life of the transmission. There is an external filter near the radiator that does need to be changed.

 

Wouldn't you disconnect one of the lines going into the trans oil cooler and flush it out while filling/topping off fluid? This would allow the fluid to cycle through. This is what should be done when switching to synthetic ATF. You want to make sure you get as much of the old fluid out.

 

You can do that on some transmissions, but not on a TorqShift. I wrote a procedure that is in the 7.3L FAQ, but that won't work on a TorqShift.

The TorqShift has a thermostat. If you don't keep the transmission above 170F the whole time it won't send fluid through the cooler lines, it will just recirculate it inside the trans. You'll need to keep the fluid you are adding above 170F, too, or it will cool off the thermostat.

 

I thought all Excursions have the 4R100 transmission? TorqShift is only on the F250+ as well as the 3V V10s.

 

My 6.0 doesnt have a 4R100 in it. It is a 05 excursion 6.0 I have seen very few 4 speed 6.0 excursions.

 

Why would Ford put a thermostat in there? It's just another part that could get stuck and overheat the transmission. Plus, it complicates changing the fluid. What is the benefit of having it?

 

All 7.3L and V10 Excursions had the 4R100. All 6.0L trucks, Excursion or F Series, had the TorqShift.

You've seen very few 4 speed 6.0L Excursions because exactly ZERO were built. Ford NEVER mated a 6.0L to a 4R100 transmission.

The benefit is quicker transmission warm ups. It increases fuel economy and prolongs the life of the transmission. Without the thermostat the trans won't warm up very quickly and that isn't good for it.

 

Mark,

Just for clarification, you designed the 4R100 and TorqShift transmissions, correct?

 

No, I did not design either transmission. I was part of the team that designed and developed the TorqShift. I also worked on other transmissions at Ford over the years.

 

So, intimate knowledge of the TorqShift and a more than working knowledge of the 4R100. Plus, a wealth of knowledge and experience on transmission design and operation in general and Ford transmissions in particular.

Fair enough?

This may seem like an obvious question for you, but is it possible/feasible/practical to pair a 7.3 PSD with a TorqShift tranny? I'm guessing it isn't but thought I'd ask the expert.

 

That's a fair assessment.

It's possible to mate ANY engine to ANY transmission. All it takes is time and money. Sometimes a little, usually a lot of both. Mating a TorqShift to a 7.3L and making it work as well as a stock 6.0L/TorqShift will probably cost a lot more than just buying a brand new loaded 2011 truck.

Mating the trans to the engine will only take adapter plates. Custom machined adapters shouldn't cost more than a couple grand. But this is just getting started....

Now you need to create a wiring harness. There isn't one in existence for this combination. That's also relatively easy. It's only a bit harder and probably more expensive than machining the adapter. But next comes the fun part.

You need to invent a computer and the software to make this work. A TorqShift is completely computer controlled. It cannot shift at all without a computer to run it. A PCM from a 6.0L/TorqShift will only work if it is controlling both the engine and transmission. It won't control the transmission if it isn't also controlling the engine. It won't know what to do with a 7.3L engine, they are very different than a 6.0L. A PCM from a 7.3L/4R100 won't even come close to controlling a TorqShift. It doesn't have anywhere near the inputs or outputs to do the job, much less the computing power to be able to do all of what needs doing.

I've heard that an aftermarket company makes a stand alone controller that will control a TorqShift. I would be VERY surprised if it can do more than just select what gear to be in. If it can actually shift gears while under power that would be a HUGE achievement. The TorqShift is a very hard transmission to make shift correctly.

 

I would have the dealer flush the tranny with new fluid.

Replace external tranny filter (passenger side near radiator).

Then when done with "flush" drop the pan (will loose 8qts of new fluid)... but then change ouot the internal filter/screen and clean/check the pan for any issues (probably none... but good to check.

Top off with 8 or so qts of fluid, check for proper fill and your good to go with 100% new fluid and new filters (internal and external). The next change will be in 30,000 miles.

I personally would do the transfer and both diff's... no matter what Ford states, the rear-diff fluid is not lifetime fluid. I change mine out every 60,000 miles (front/rear and transfer case)... and for the piece of mind it is worth it.

Now, if you have less than 60,000 miles on your diff's, your probabaly good until 80,000 miles... but that is your call... but I would do the transfer case when you do the tranny (use only Mercon V in transfer case and Mercon SP in the tranny). They are not interchangable or mixable.